Summary

It is the largest body in the asteroid belt, yet Ceres is not an asteroid. Nor is it a planet. Ceres is a dwarf planet, and like its more famous cousin in the outer solar system, Pluto, Ceres harbors a lot of ice. This has astrobiologists salivating at the arrival of NASA's Dawn spacecraft, which will begin orbiting Ceres on 6 March. Scientists suspect that Ceres was massive enough for its rock and ice to separate into layers. There is evidence that Ceres's icy mantle was once a watery subterranean ocean, and there are hints that this liquid may remain even today. Dawn will map the surface, seeking evidence that this liquid occasionally erupted at that surface.